Environmental Emergencies
Question 130 of 300
A 32 year old hospital laboratory technician presents to the Emergency Department. He tells you he has been working in the haematology lab and is involved in the irradiation of blood products. He has not been wearing the approved personal protective equipment for the last month. He is complaining of a burning feeling in both hands. On examination you find no abnormalities. What is the management of this patient?
Answer:
This patient has been irradiated but not contaminated. Patients who are exposed to external beam radiation are not made radioactive and are not a hazard to others. Decontamination and isolation are not necessary. With a normal physical examination and minimal symptoms, this patient can be followed as an outpatient. The most important action in this instance is to educate the patient.Radiation Injuries and Illnesses
Environmental Emergencies
Last Updated: 19th February 2023
Types of radiation
There are two major types of ionising radiation:
- Electromagnetic radiation (external radiation: gamma rays and x-rays)—Passes through tissue, irradiating casualties but leaving no radioactivity behind.
- Particle radiation (alpha and beta particles)— Does not easily penetrate tissue. (The amount of radiation absorbed by cells is measured in Grays (Gy) or new international standard of radiation dose the rad, 1 Gy = 100 rad.)
Radiation exposure can consist of external contamination, localised or whole body, or internal contamination. With external contamination, radioactive debris is deposited on the body and clothing. With internal contamination, radioactive debris is inhaled, ingested or absorbed. Assume both external and internal contamination when responding to disasters involving radioactive agents.
Radioactivity can easily be detected with:
- Geiger counters
- Area survey meters
- Personal dose-rate meters
Radiation threat scenarios
- Nuclear detonations
- Three types of injuries result from nuclear detonations:
- Blast injuries - overpressure waves
- Thermal injuries - flash and flame burns
- Radiation injuries - irradiation by gamma waves and neutrons and radioactive debris
- Three types of injuries result from nuclear detonations:
- Meltdown of a nuclear reactor
- Core must overheat causing nuclear fuel to melt
- Containment failure must occur, releasing radioactive materials into environment
- Radiation dispersal device
- Conventional explosive designed to spread radioactive material
- No nuclear explosion
- Simple radiological dispersion
- Simple radioactive device that emits radioactivity without an explosion
Clinical effects of radiation
The medical effects of radiation include focal tissue damage and necrosis, acute radiation syndrome (ARS), and long-term effects that can persist for weeks to decades, such as thyroid cancer, leukaemia, and cataracts.
Radiation burn:
- In the acute setting, a radiation burn appears similar to a thermal burn with signs of:
- Erythema desquamation (dry or wet)
- Blistering
- Oedema
- Pain
- The long-term sequelae are:
- Vascular insufficiency
- Ulceration
- Necrosis
- Acting as an entry point for infection in a potentially immunocompromised patient
Acute radiation syndrome (ARS):
- Group of clinical sub-syndromes that develop acutely (within several seconds to several days) after exposure to penetrating ionising radiation above whole-body doses of 1 Gy (100 rads).
- ARS affects different systems, depending on the total dose of radiation received.
- Lower doses predominantly damage the haematopoietic system.
- Increasing doses damage the gastrointestinal system, the cardiovascular system, and the central nervous system, in that order.
- The higher the exposure, the earlier symptoms will appear and the worse the prognosis.
- Phases:
- Prodromal phase
- Symptoms may include nausea, vomiting, diarrhoea and fatigue
- Latent phase
- Length of phase is variable depending on exposure level
- Patients may be relatively asymptomatic with fatigue and bone marrow depression
- A reduced lymphocyte count can occur within 48 hours and is a clinical indicator of the radiation severity
- Manifest illness
- Clinical symptoms associated with major organ system injury (marrow, intestinal, neurovascular) - e.g. gingival bleeding, epistaxis, petechiae, systemic infections and gastrointestinal symptoms lasting up to 4 weeks
- Death or recovery
- Prodromal phase
Management of radiation
- General measures dealing with managing the incident
- Preparation
- At the planning stage, consideration must be made for command/control issues, nominating organisation responsibility, personnel training, notification criteria and obtaining appropriate equipment such as protective clothing.
- In most emergency departments (EDs), senior medical and nursing staff will have chemical, biological, radiological and nuclear (CBRN) training and will be familiar with the response plan and equipment for that hospital. The safety officer or a deputy for the radiotherapy department should be involved in a significant radiation incident.
- Acute crisis management
- In the acute crisis management stage, one must consider how to:
- Triage and deal with injured patients
- Limit further exposure to population and personnel
- Organise decontamination and evacuation
- In the acute crisis management stage, one must consider how to:
- Personal safety
- Recommendations about exposure are:
- At 0.1 mGy/h, personnel can enter and give life-saving or time-critical treatment
- At >0.1 mGy/h, exposure is life-threatening so personnel should not proceed
- All staff dealing with contaminated patients should wear protective clothing and carry a personal radiation meter.
- Recommendations about exposure are:
- Initial assessment and triage
- Initial assessment should be based on the airway, breathing, circulation (ABC) system, allowing categorisation of patients into two groups: those with life-threatening injuries and those with non-life-threatening injuries.
- All patients with life-threatening injuries should be treated as contaminated and evacuated to a medical facility that has been pre-alerted to their arrival.
- Patients with non-life-threatening injuries and the non-injured population should be evacuated upwind and then formally assessed for contamination.
- Decontamination
- On-scene decontamination is usually not possible if large numbers of people have been affected.
- By removing clothes, up to 90% of contamination is removed. Exposed individuals are then hosed down with warm water (to prevent hypothermia) and detergent.
- Decontamination should use the rinse-wipe-rinse; system. It is important not to abrade the skin barrier during decontamination. All contaminated materials and water must be disposed of appropriately.
- Preparation
- Specific measures for the exposed patients
- Isolation procedures
- The ED receiving patients from the exposure zone should be divided into areas to deal with those who are radiation-contaminated and those who are not.
- Safe transfer of patients between areas can be achieved by wrapping each patient in a sheet, which limits cross-contamination.
- When patients arrive, they can be further segregated into those who are externally contaminated only, internally contaminated only, and those with combination injuries and trauma associated with detonation devices such as blast, flash and thermal injuries.
- External radiation injuries
- Wounds should be rinsed with saline and left open until debrided and decontaminated. Surgical excision of some long half-life materials may be required. After this, wounds should be closed or covered to prevent entry of infection. In addition, the clinical approach is to provide adequate analgesia and antibiotic prophylaxis as well as considering vasodilator therapy and referring the patient for plastic surgery for definitive grafting/amputation as appropriate.
- Internal contamination
- The aim of internal contamination is to reduce the overall radiation dose by strategies for reduction of absorption, dilution, blocking, displacement by non-radioactive nucleotides, increased elimination from tissues, chelation and decorporation. The particular strategy will depend on the radioactive substance to which the patient has been exposed. For example: decorporation, which is the removal of internal contamination by exploiting the chemical and biological properties of the radioisotope; Prussian blue is used for caesium exposure or bicarbonate for uranium exposure.
- Acute radiation sickness
- Supportive treatment
- IV fluids, antiemetics, analgesia, nutritional support, antibiotics, antifungals, antivirals, blood component substitution, reduction of cerebral oedema (mannitol and ventilation strategies).
- Long-term management
- Potassium iodide or iodate is given to prevent radioiodine in thyroid accumulation.
- Options for definitive therapies include stimulation therapies such as granulocyte-stimulating factor (GSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), bone marrow transplant or stem cell therapy.
- Supportive treatment
- Isolation procedures
Report A Problem
Is there something wrong with this question? Let us know and we’ll fix it as soon as possible.
Loading Form...
- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
